The concept of numbers are originated from the need of counting real things. Like objects or the days in a year. Now we can divide numbers in different groups. We will discuss one by one. Here is a list of Various types of numbers.
Every Day we use various chemicals in different form. I varies from edible salt to Detergent. Knowing their chemical names and chemical compositions comes handy in indian govt job study and indian govt jobs competitive exams. Here is a list of 15 daily used household chemicals and their composition. You can download this image for future use.
Remembering Square/square root-cube/cube roots of numbers comes handy when calculation time is a big factor, like in competitive exam.
You can easily remember
Square/square root-cube/cube roots of numbers
up to 20. For remembering after 20, you need to read the table again and again.
There is a trick to quickly calculate rather than remembering